Engine Insulation

[Mudgey]

Hello,

The car:
Supercharged K20 Prelude.

The problem:
I tend to do about 4 very short journeys each day, approximately 2.5m each! The car then sits on average 3 hours between each journey. The car hardly ever gets warm enough to open the thermostat and this must be killing the fuel economy and of course is also not good for the engine! By the time I get to work the engine may be 65c but is close to ambient again within those 3 hours! Currently the weather is approx 3c but can get as cold as -5.

Potential solution:
I thought about making and installing a vacuum flask/insulated container for engine coolant, but then thought why not just insulate the whole engine? So I am thinking about creating an engine blanket to cover the whole motor & possibly gearbox too. One issue is the supercharger and they have a max operating temperature so it may be worth insulating around the inlet manifold only with the charger exposed. I am thinking I will insulate the non cooling parts of the radiator and the water pipes also. I also have an engine pre heater to install but has anybody ever done anything like this and what sort of results have you had?

1. I imagine if the whole engine is covered in a blanket everything within that is going to warm up to approx coolant temp which is 85c, is it detrimental to the wiring or any other part of the engine for everything to be this hot?

2. Is the gearbox ok working at a sustained higher temp? I feel if this part was left expose it would essentially act as a heat sink.

3. Whats the best thing to do about the exhaust? I was thinking of tailer making something to have an inch gap or something around the exhaust headers so the insulation doesn't get too hot though it would have to hug the block around the exhaust area so it doesn't touch it.

[Frank Lee]

Search "engine blankets" here.

You definitely can benefit from one. Or better yet, a bicycle, electric bicycle, or scooter.

I just make engine bay covers with little to no attempt to "wrap" the engine and vitals. They are functional all year; no overheating in the summer.

[XYZ]

Originally Posted by Mudgey

Hello,

The car:
Supercharged K20 Prelude.

The problem:
I tend to do about 4 very short journeys each day, approximately 2.5m each! The car then sits on average 3 hours between each journey. The car hardly ever gets warm enough to open the thermostat and this must be killing the fuel economy and of course is also not good for the engine! By the time I get to work the engine may be 65c but is close to ambient again within those 3 hours! Currently the weather is approx 3c but can get as cold as -5.

I have the same problem: short, essential trips and the car hardly ever gets up to operating temp. For those of us with this situation a block heater is useless.

Potential solution:
I thought about making and installing a vacuum flask/insulated container for engine coolant, but then thought why not just insulate the whole engine? So I am thinking about creating an engine blanket to cover the whole motor & possibly gearbox too. One issue is the supercharger and they have a max operating temperature so it may be worth insulating around the inlet manifold only with the charger exposed. I am thinking I will insulate the non cooling parts of the radiator and the water pipes also. I also have an engine pre heater to install but has anybody ever done anything like this and what sort of results have you had?

The potential problem is that it might get too hot, even in winter, if you travel any distance that is longer than your usual short distance.

If you wrap the engine in any sort of wrap, your insulating blanket will certainly become very dirty. And you will need to remove all the intricacies of however it is attached during warmer weather.

1. I imagine if the whole engine is covered in a blanket everything within that is going to warm up to approx coolant temp which is 85c, is it detrimental to the wiring or any other part of the engine for everything to be this hot?

Maybe. But it wouldn't be good to find out the hard way, that it's detrimental.

2. Is the gearbox ok working at a sustained higher temp? I feel if this part was left expose it would essentially act as a heat sink.

Is it A/T or manual?

3. Whats the best thing to do about the exhaust? I was thinking of tailer making something to have an inch gap or something around the exhaust headers so the insulation doesn't get too hot though it would have to hug the block around the exhaust area so it doesn't touch it.

IMHO the blanketing idea is too cumbersome and potentially problematic, because it's difficult to uninstall it. Consider easier options: A grille block that is easily removable that can be attached over the exterior grille. Another very inexpensive and easily removable, yet highly effective item is that of simply putting a sheet of cardboard or formica panel to block the radiator. The nice part is that if the temp gets too hot you can quickly and easily remove it while on the road - and put it back when the engine cools down.

Another strategy you might want to consider is changing the spark plugs to the next step hotter in heat range. If you are constantly doing cold trips while not up to operating temp, this may help. I've done it and found it beneficial for the vehicle I use mostly in winter, for short runs. Plus the good old cardboard radiator block...

[California98Civic]

Another approach, in addition to XYZ's above, that I have seen discussed on this site is partial insulation techniques: seal the hood gaps and insulate just the hood on the inside with non-flammable materials. Make sure that insulation can be removed during warmer months. This is only likely to produce marginal improvements, if any. But like a lot of things we do with these vehicles, piling up lots of small benefits until it makes something significant can be the name of the game.

On my car, I also run with the heat selector set to "cold" because it sequesters a small amount of the coolant from circulating. Shortens warm up slightly.

Belly pan too? With a belly pan you'd have an enclosed engine compartment. If you build it with an easily removed aluminum access panel under all areas where oil and such might drip, you could easily maintain it...

james

[Mudgey]

Thanks for all your informative replies. There are some good ideas.

Without quoting, here are some answers to your points made above:

Frank Lee:
Thanks, have done a search and these seem to be flat sheets or L shaped pieces that you overlay on the engine? This is the next best thing but I wonder if we could take it a little further and run as much around the engine as possible.

XYZ:
Yea, its damaging my fuel economy. I have a block heater to go in for the mornings to get the whole lump up to temp, then the plan is keep as much of that heat as possible! Plus I also stock & sell engine pre heaters so there is no reason why I shouldnt fit one!

I don't think dirt is a problem, if anything it will keep the engine clean, this is a good thing as the car is going to be shown at car shows this year I can whip it off and not have to clean as much as I would have too!
How hot the engine gets should be goverend by the t-stat, how hot everything within the insulation gets is down to testing! Things such as the TB, alternator, supercharger, exhaust manifold etc will be outside of the engine blanket.

Car is a 6 speed manual, with a super low 6th, its geared for 189mph but will never do it!

I am not sure on the radiator block? Surely the t-stat regulates the temperature and it doesn't really matter how big the radiator is? I will be fitting an upper grill block, the car ran fine during the summer, I just haven't got around to finishing the permanent design yet!

CaliforniaCivic:
Thats not a bad idea, its fully sealed at the back but not down the sides. The car is not currently running a hood insulation sheet as the supercharger was hitting the bonnet I had to remove it to give adequate clearance. I will get another one to reinstall soon.

I could never run it cold! its needed to demist the windscreen and keep me warm, I have to have some creature comforts!!

A front half belly pan would work, I couldnt block off the entire underside of the engine bay as the car needs to vent 300hp worth of heat at full chat.

[Frank Lee]

Originally Posted by Mudgey

Thanks, have done a search and these seem to be flat sheets or L shaped pieces that you overlay on the engine? This is the next best thing but I wonder if we could take it a little further and run as much around the engine as possible.

I am not sure on the radiator block? Surely the t-stat regulates the temperature and it doesn't really matter how big the radiator is? I will be fitting an upper grill block, the car ran fine during the summer, I just haven't got around to finishing the permanent design yet!

I use FLAMMABLE corrugated cardboard on the cars because as on yours, engine bits-to-hood clearance is almost non-existent. The F150 has the luxury of enough clearance for 1" foil faced foam sheet.

If you can more fully enclose the engine, be my guest. My engine bays all are a potpourri wires, hoses, lines, linkages, hot bits, and sticky-outy parts; to enclose that mess would be quite the project. I think that because heat rises, insulating only the top gives the most benefit and besides, since I haven't "overdone it" the cooling system retains functionality when the vehicle is going, even in the summer. A grille block serves to reduce the breezes that cool the compartment down even further. One caveat: because the F150 is fanless and is called upon to work hard, the grille block comes out in the summer, but the cars stay the same year-around. So it is pretty much a set it and forget it system.

[2000mc]

Originally Posted by California98Civic

...seal the hood gaps...

i dont know how well this transfers to sitting still, but...
my IAT used to generally display outside temp, as long as the car was moving. i added foam tape across the front edge of the hood and around the headlights (at the time only done for the tiny aero benefit) and inadvertently created a mild warm air intake. temps generally running roughly 20-30deg above ambient temps at highway speeds after the engine is warmed up. the air intake does sit just behind one of the headlights

[XYZ]

Originally Posted by Mudgey

I don't think dirt is a problem, if anything it will keep the engine clean, this is a good thing as the car is going to be shown at car shows this year I can whip it off and not have to clean as much as I would have too!

The blanket will keep the engine clean, but the blanket itself will get dirty over time - which might be a chore if you need to remove it.

How hot the engine gets should be goverend by the t-stat, how hot everything within the insulation gets is down to testing! Things such as the TB, alternator, supercharger, exhaust manifold etc will be outside of the engine blanket.

Also consider installing a higher temp thermostat, if there is one that will fit your car.

I could never run it cold! its needed to demist the windscreen and keep me warm, I have to have some creature comforts!!

For comfort, buy an add-on seat warmer that plugs into the lighter socket. They are inexpensive and they work well. It will keep your butt happy while waiting for the heater to produce heat.